Analog Digital Manual chp 1
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In this chapter they use a POT, OP AMP, and an LED. Im wondering if you can
vary an LED's brightness with just a POT, VDC, and an LED or do you need the OP
AMP?
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vary an LED's brightness with just a POT, VDC, and an LED or do you need the OP
AMP?
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Yahoo! SiteBuilder - Free web site building tool. Try it!
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Comments
with just a POT. BUT, the next step in
the lab is to replace the POT with a
resistor-capacitor combination, charged
with a software command from the BS2.
For this command to work, you need to
have the op-amp there. An op-amp has
a very high input impedance, so it
takes very little charge from the
capacitor, so the capacitor
can maintain its charge. This is
the heart of a simple (cheap)
D to A converter.
Just so you know, an LED's output is
usually full on or full off. You can dim
it by finding that narrow range of currents
where it is partially on, which is what
this lab does.
--- In basicstamps@yahoogroups.com, Jimmy jones <cantyant@y...> wrote:
> In this chapter they use a POT, OP AMP, and an LED. Im wondering
if you can vary an LED's brightness with just a POT, VDC, and an LED
or do you need the OP AMP?
>
>
>
>
>
> Do you Yahoo!?
> Yahoo! SiteBuilder - Free web site building tool. Try it!
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
that helps for now, I will need to absorb that.
Allan Lane <allan.lane@h...> wrote:
Yes, you can vary an LED's brightness
with just a POT. BUT, the next step in
the lab is to replace the POT with a
resistor-capacitor combination, charged
with a software command from the BS2.
For this command to work, you need to
have the op-amp there. An op-amp has
a very high input impedance, so it
takes very little charge from the
capacitor, so the capacitor
can maintain its charge. This is
the heart of a simple (cheap)
D to A converter.
Just so you know, an LED's output is
usually full on or full off. You can dim
it by finding that narrow range of currents
where it is partially on, which is what
this lab does.
--- In basicstamps@yahoogroups.com, Jimmy jones wrote:
> In this chapter they use a POT, OP AMP, and an LED. Im wondering
if you can vary an LED's brightness with just a POT, VDC, and an LED
or do you need the OP AMP?
>
>
>
>
>
> Do you Yahoo!?
> Yahoo! SiteBuilder - Free web site building tool. Try it!
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
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